#include<iostream>

int main(int argc,char **argv){
    float A_price,B_price,B_postage,num;
    std::cout<<"请输入包邮A店单价和B店单价与运费,以空格隔开,以空格结束"<<std::endl;
    std::cin>>A_price>>B_price>>B_postage;
    num=B_postage/(A_price-B_price);
    std::cout<<"当购买数量小于等于"<<num<<"时,在A店买,否则在B店买"<<std::endl;
    return 0;
}